How to Kill Carpenter Ants That Are Attacking an Oak Tree

by Shelley Marie

Contrary to popular belief, carpenter ants do not consume wood.

Carpenter ants have large black or black and red bodies, with workers reaching up to one-half inch and queens up to 1 inch long. They thrive in colonies and build nests in soft, hollowed-out or rotting wood. They feed on sugar, protein and insect honeydew. Carpenter ants aren't typically harmful to trees, but controlling them can prevent an infestation in your home or elsewhere on your property. Oak trees (Quercus spp.) grow in U.S. Department of Agriculture plant hardiness zones 3 through 9. If you have carpenter ants in your oak tree, the best way to kill them is by attacking the entire colony.

1

Locate the carpenter ant nest in the tree. Look for the nest entrance in areas with rotting wood, soft spots or piles of sawdust. If you disturb the nest, ants carry the white pupae and larvae to a safe location. Since the ants travel mostly at night, use a flashlight covered with red cellophane to observe their movements and locate the nest.

2

Fill the nest entrance with dust insecticide containing carbaryl or rotenone. Wear gloves and goggles when applying the insecticide. Pour the dust into a hand duster or a clean empty condiment bottle with a tube tip. Insert the tip into the nest entrance and squeeze the bottle to release the dust into the hole. Alternatively, use a spray insecticide containing bifenthrin, deltamethrin, esfenvalerate, lambda-cyhalorthrin, permethrin, or pyrethrin on the nest. Reapply the insecticide as needed according to the label instructions.

3

Cut back the oak tree's branches with loppers if they come in contact with your home, to prevent an indoor infestation. Do this during the fall or winter to prevent oak wilt.

Things You Will Need

Flashlight

Red cellophane

Dust or liquid insecticide

Gloves

Goggles

Hand duster or empty condiment container

Pruning loppers

Tips

Sugar-based carpenter ant baits placed near the nest can work for small infestations.

Warnings

Take care when handling insecticides and pruning loppers. Keep children out of the area when using these items.

About the Author

Shelley Marie has been writing professionally since 2008 for online marketing and informational websites. Her areas of expertise include home, garden and health. She holds a Bachelor of Science in business administration and an associate degree in medical billing and insurance coding, both from Herzing University.

Photo Credits

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